This invention relates to novel polyether derivatives useful as a carrier for transporting cations from one aqueous liquid to another aqueous liquid.
Concentration and extraction of cations such as metal ion become very important techniques in many fields such as biochemical and radiochemical arts. Especially, there is an increasing demand for a method for the selective separation of lithium which is utilized in a variety of fields such as for the production of tritium. Certain compounds such as 12-crown-4 and cryptate [2,1,1] are known to have a specific affinity to lithium ion and are proposed to be used for the separation of lithium ion. However, the known ether compounds are not satisfactory since lithium ion once captured by the ether compounds can not be easily released therefrom and since the separation of lithium ion by such ether compounds is greatly influenced by the kind of other coexisting cations.